The present invention relates to a cultivator and more particularly to a cultivator which is adapted for use in conditioning the earth surface along row crops, such as cotton, permitting precise control of the earth environment for the crops.
The raising of certain row crops, such as cotton, on a commercial scale presents particularly acute problems of soil control. After the seed has been planted but before the seedlings have penetrated the earth surface, soil conditions frequently inhibit or preclude the emergence of the seedlings. A rain following planting usually produces a surface crust through which the seedlings are unable to emerge. When this occurs, the farmer usually tries to break up the crust by comminuting the soil along the rows by rolling toothed wheels thereover. Although for many years this has been recognized as the best available procedure, it as been notoriously ineffective. The toothed wheels damage the sprouting seeds and thus in many instances destroy that which they are intended to save. They damage or destroy the plants which have emerged. In any event, the resultant stand is seriously impaired and many gaps occur in the rows. There being no way for a cultivator, spray equipment, or irrigation water to distinguish between portions of the rows having proper plant spacing and those having no plants, the gaps must be farmed the entire season just as tediously, laboriously and expensively as portions of the rows having proper plant spacing. For these reasons, many cotton farmers recultivate and completely replant whenever their fields become crusted prior to plant emergence. While this procedure has been the only one capable of insuring a proper stand, it is expensive and results in a shortened growing season with proportionately restricted crop production and quality.
The present invention results from the discovery that the objectionable features of both procedures can almost always be avoided by the provision of a cultivator capable of precise control which can shave off the crust whenever it occurs without such variations in depth control as to impair the sprouting seeds. A virtually totally effective procedure is found to be the planting of the seeds at a slightly greater depth than normal so as to accommodate an accurately controlled removal of a thin surface layer of the soil, whether crusted or not, after the seeds have germinated but before the sprouts have reached to within a quarter of an inch or so of the surface. Thus the seedlings can emerge through loose soil and a good stand can be attained in spite of late rains.
Crusting soil also acts as a barrier to the most effective utilization of soil additives. Fertilizers, herbicides, fungicides, and the like applied to the earth surface are impeded from most effectively permeating the soil by the presence of such a crust particularly where the earth slopes away from the rows on the opposite sides thereof, as is the normal condition in row crop farming.
Conventional cultivating implements are not suitable for working the soil where such conditions exist, particularly immediately adjacent to the plants. The unwieldy construction of such implements as well as their propensity to work the soil at depth rather than just at the level of the surface crust severely limits their utility under such conditions. In this connection attention is invited to the following U.S. Patents which were either cited against the parent application or called to the attention of the Patent Office by the applicant:
Patent No. Applicant Issue Date ______________________________________ 166,044 Weaver 7-27-1875 326,917 Priest 9-22-1885 952,663 Zindorf 3-22-1910 1,067,589 Dawson 7-15-1913 1,245,107 Hughes 10-30-1917 1,477,846 Okamoto 12-18-1923 1,540,100 Carter 6-02-1925 1,549,031 Spurling 8-11-1925 1,969,204 Carlson 8-07-1934 2,309,847 Holton 2-02-1943 2,660,817 Thomas 12-01-1953 2,739,517 Roberts 3-27-1956 2,985,248 Richardson 5-23-1961 3,306,240 Ritchie 2-28-1967 3,474,869 Mowbray et al 10-28-1969 3,552,498 Stauber 1-05-1971 3,684,029 Clover 8-15-1972 12,463 Austrian 7-10-1903 25,742 Swedish 6-07-1907 ______________________________________
Therefore, it has long been recognized that it would be desirable to have a cultivator adapted to be precisely controlled to limit the depth and character of soil cultivation thus minimizing the disturbance of seeds or growing row crops while most advantageously conditioning the soil.